1. Field of the Invention
This invention relates to the art of label printing and applying apparatus.
2. Brief Description of the Prior Art
U.S. Pat. No. 1,665,467 to David B. Miller dated Apr. 10, 1928 discloses a stamping device in which a pivotally mounted hammer is tripped into printing cooperation with a marking stamp.
U.S. Pat. No. 3,408,931 to Charles C. Austin dated Nov. 5, 1968 discloses a hand-held label printer in which a print head is mounted for straight line reciprocating movement. This patent discloses cocking means responsive to an actuator for moving the print head from printing to a retracted position during the cycle, a detent for holding the print head in the retracted position during a subsequent part of the cycle, and trip means responsive to the actuator at or near the end of the cycle to disengage the detent, thereby permitting a spring to snap the print head into printing position.
Published German patent application No. P 23 45 249.5-27 (2530346) and its corresponding U.S. Pat. No. 4,072,105 of Meto International GmbH disclose a hand-held labeler having an actuating lever and a spring-urged print head lever. The spring may be cocked by swinging the actuating lever up to the point of reaching a spring force which is greater than the maximum of resistance opposed to the movement of the printing mechanism toward the platen. When this occurs, the print head will be snapped against the platen with constant force independent of the force or speed of movement of the actuator level.
U.S. Pat. No. 3,911,817 to Werner Becker et al dated Oct. 14, 1975 discloses a device for printing and dispensing labels in which a printing mechanism and a label strip advancing mechanism are actuated by movement of a secondary lever and the secondary lever is moved by a primary lever only after actuation of the primary lever to exceed a predetermined biasing force tending to maintain the secondary lever stationary.
U.S. Pat. No. 3,957,562 to Paul H. Hamisch, Jr. dated May 18, 1976 discloses a hand-held labeler having a frame with a handle, an actuator disposed at the handle, a gear segment carried by the actuator, a gear having a gear segment meshing with the actuator gear segment and another gear segment meshing with a print head gear, movement of the actuator effects direct movement of the print head through the gears without any lost motion. The labeler also includes a platen with which the print head is cooperable, a delaminator for delaminating labels, an applicator for applying printed labels and a pawl and ratchet mechanism effective when the actuator is released to advance the web. Other prior art disclosing hand-held labelers, in which the printing mechanism is triggered to control impression, are German Offenlegungsschrift No. 2,656,862 and German Offenlegungsschrift No. 2,729,097.